Improvement in hot-air engines



v v 4 sheets-sheen 1. C. W. BALDWIN.

HUT AIR ENGINE.

N0. 46,320. 'Patented Feb. 14, 1865*.'

Sheet 2.

4 Sheets Patent-ed Feb. 14, 1865.

O. W. BALDWIN.

HOT. AIR ENGINE.

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, 4 Shee'tS-Slheet 3. C. W. BALDWIN.

, HOT AIR'ENGINE. No. 46,320.

Patented Feb. 14, 1865.

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4 Sheets-Sheet 4,

C. W. BALDWIN..

HOT AIR ENGINE No. 46,320. Patented Feb. 14

UNITED rSTIV-rus A"Pirrluvr OFFICE.A

crans W. BALDWIN, or oHAgRLEsTo'WN, MAs'sAcHUsn'r'rs |MPRovI-:MENT INl HOT-Am ENGINES. I

, Specification forming part of Letters Patent 190.46320, dated February 14,1665.

To all'whom it may concern:

Be it knownthat I, CYRUS W.- BALDWIN, of

Charlestown, in the county of-Middlesex, in lthe State of Massachusetts, have invented Imto rapid deterioration from heat, and afford Y facility for replacement-of parts which Wear orA f burnout. y

The invention consists in the peculiar arrangement of a disk-valve so as'to be guided at its periphery in connectionwith the casing and passages making they valvular system;` also, in the introduction of a ,secondary tirebox into the passage between the main fire-box and the valve-chamber, so thatv by means of a name created in said secondary virebox the unconsumed gases escaping from the primary fire-box may be burned by coming into con-- tac'twitli the flame in the secondaryfirebox, which flame may be produced by ignition of gas-jets, oil, petroleum, or other combustible matter, and in making the passage through which the air is suppliedk above `thegrateto the fuel so that the air-passage can be .inter changed with the rings of the furnace-lining,

and thus be made to pass air-into thefurnace higher or lower into the fuel or entirely above it, as the circumstances attending the work to be done, the fuel yused, and experiencey may dictate or require. f

Four sheets of drawings accompany this specification, on which sheets Figure l represen ts a general side elevationof an engine embodying my improvements. Fig. 2 is a vertical longitudinal section of the same, the sec tion being taken in the plane of vthe lines x w.' (Seen on 4Sheets 3 and 4.) cross-section of the sa1ne ,.the section being taken 'in a pla-ne passing through-the axes of the cylinder Iand of the induction-'valve stem.

Fig. 4 is an end elevation of the same looking at the air-pump end of the engine. Fig. 5 is it reversed plan of the engine bed-plate and Fig Fig. 3 is a verticall 6, a horizontal section taken tlII-oughy the bedplate in its reversed position, said figures and Fig. 7 ,which is a plan ofthe engine bed-plate stripped of the air-pump, engine-cylinder, and furnace, illustratingthe valvular system and air-passages pertaining to the 'air-pump. Fig. 8 is a vertical section taken inthe plane ofthe vline a b. (Seen in Fig. 7.) Fig. 9, Sheet 2, is a vertical section `taken throughy the enginevalves and valve-chest, in the plane of the line y y. (seenin Fig. 4.)

, As the general. organization and method of operation of hot-air engines is now well known, the description which follows, relating to con,-v struction and operation, as illustrated vby the drawings, ywillbe confined nearly as possible tothe embodiment of my invention before stated.

c is 'the outer vcasing of the-furnace.y v d is the lining thereof, made in .separate rings and in segments. eis the passa-ge byl which lair is supplied to the fuel above thegrates.v Both the passage eand the lining. cl are-removable, and it will be obvious that e may be placed next above the'grate and below all of the lin-l in g-rin gs d, orit--the passage e-may be placed betweenany of the lining-rings d, ast may be desired. f.

The wall of. the furnace has a slotted open-- ing into the air-supply pipe, or perforations aremade through the wall into said pipe, so that Wherever the ring c isv placed the air will flow freely into it from the supply-pipe'.

. Theengine-cylinder, as is usual, is divided into two parts, an upper and a lower one, the lupper part ofl the piston being packed in the upper part of the cylinder, as is usual, and

the lower part of the piston working loosely in the lowerpart of the cylinder, as usual. Between thesel two parts of the cylinder is located a water-passage, f, which in'section is H-formed and extends entirely around -t-he cylinder as a ring between .thetwo parts. In' the middle or connecting piece of this passage f are holes, (see FigsQZ and 3,) which permit free circulation'ot water therein, this being supplied to f in a cold. state'by one of the pipes g,'andtaken therefrom when lieatedby the other pipe g, thesev pipes g bein g arran ged as is usual in' heatedlwater circulation systems.

Thus the heat which vwould without intervenl tion of f beconductedfrom the lower to the upper part of the en gine-cylinder is intercepted and carried off by the water passing through j',

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and experience. shows that the heat which the upper part of the cylinder receives from direct contact'with the hot V'products of combustion from the furnace is kept 4down by radiation therefrom, so that the leather packing of the good non-conductor. Hct-air engines have' had the furnace thereof directly in the lower part of the cylinder, or beneath it, or inca-sed with it in such a manner that by reason of unequal expansion ot' parts and conducted heat the deterioration of the engines has been very rapid, owing to the burning out ot' the working parts and tlie breakage and leakage consequent upon unequal expansion. To rernedy these diiiculties I isolate myV furnace l from the cylinder .and the engine valvechest,

the bed-plate being the only means of con-` ducting heat between the cylinder and fur-v n ice, and the pipe 'i the only means of cornmnnication between the furnace and the valvechamber j. -As the tendency of heat is .upward, andas the space in the furnace below the grates is supplied with cold 'air'from the air-pump, no heat, it is found in practice, is communicated to the cylinder from the furnace by the connection ot' the bed-plate.

To allow of expansion and contraction the pipe t'. is made of considerable length, with crooks or curves therein, and of thin metal, so that of itself it conducts but very little heat, though iteonveys the heated volatile products of combustion. In the pipe z', between the furnace and the valve-chest, is an auxiliary fur'- naee or chamber, 7rwhic'h may be supplied with means for consuming therein, with a flame, gas, oil,'petroleu1u, or other suitable combustible substance.

lart of the fuel in the large furnace i's changed bythe heat therein to volatile gases which do not burn when they are generated, but which will burn if, while they are het, they are brought directly into contact lwith flame. To supplysuch atlante, through which all the'volatile products of combustion from the large furnace must pass, the small furnace 7c is supplied as stated, and the results which follow its application are found in practice to be hi gli-ly beneficial. i

In hot-air engines it is of special importance that the exhaust-valve should lit its seat perfect] y, for if at the time the induction-valve is open the eduction-valve lea-ks there is nothing to prevent the gaseous contents of the cylinder and furnace from escaping past the leak; hence it is important that special provision should be made for examining the condition of the joint made by the exhaust-valve with Vits scat, and lor repairing any deterioration therein as soon as it becomes sensible. lly

reference toFig. 9, the exhaust-valve l will be seen as closedupon its seat. This is'fcrmed on the end of a tube or thiinbltamz, which is provided with aiiange, sol that when on is inserted into the valve-chest)l the flange on on makes the joint with the valve-chest, and the eXhaust-pipecan be Vconnected with that end of m which is outside of the valve-chest. lt

willbe seen that this piece m can readily be removed from the valve-chest, can be faced anew in the lathe very readily where the valve rests upon it, so that it is a matter of but small moment to keep this valve-seat so constructed and arranged 'in constant working order.y

The arrangement of the air-pump so that a vertical plane passing through its axis shall intersect the axis of the main shaft so places the pump that it att'ords the best and cheapest stand possible for the support of the mainshaft boxes n and simplifies and cheapens the construction of the engine.A The valves of the air-pump, `which are of the exibledisk variety, a-re peculiar in that they have no hinge and are not guided of al central rod. By reference to Fig. 8, Sheet 4, it will be seen that the ed'uction-valve o rests freely on a llat seat, being prevented byagrating from being forced through theaperturewhichit closes. The valve is guided at its periphery by pins or rods standing up vertically around the valve-seat and in cont-act, or nearly so, with the edgeot the'Val-ve, which, in its rising and falling, is

thereby keptin place. These guides might be formed as wings or rid ges ,extendin g from the cap p inward toward the valve. This cap is is arranged eccentrically4 over and with respect to the valve, which gives room furthe kcrescent-shaped eduction-pipe seen in Figs.

6 and 7, which is formed beyond the valve and between it and the inner boundary of the cap or chamber p. The arrows seen on the various figures indicate they directions of the various currcntsin theoperatio'n of the engine I claim- L'Guiding a fiexible-disk valve, substan' tiallyas described.

2. Also, the employment of a secondary tur nace in combination with the primary furnace and the cylinder of ahotair engine when located so that .the products `of combustion from the primary ,furnace go through the sec# ondary furnaceon their passage into the cylinder, ysubstantially as and forthe purpose set forth. 1

3; The arrangement in the furnace, in connection .with a suitable opening oropenings through the wall thereof into the air-'conduit pipe, of a perforated movable air-passage ring, so as to beinterchangeable with the movable.

lining-rings.

ln witness whereof I have hereuntoset my hand thislSth day-of October, A. D. 1864. l CYRUS W. BALDWIN.

Witnesses J. B. Gnosnv, ALBERT F. HALL, 

